The present invention relates to the removal of contaminants, particularly to the removal of contaminants from an aqueous media, and more particularly to the removal of contaminating metals and organic compounds from an aqueous media using solid material, which may be in the form of sol-gel and/or sol-gel and with solid support mixtures, which may be in the form of granulated activated carbon (GAC).
In recent years, substantial effort has been directed to the removal of contaminants from an aqueous media, such as ground water. Numerous xe2x80x9cSuperfundxe2x80x9d sites have been established because of contamination of ground water by various materials. The main contaminants are metals, particularly uranium and hexavalent chromium, volatile organic compounds (VOCs), high explosive compounds, nitrates, perchlorates, and tritium, as well as various commercial and manufacturing waste contaminants.
Presently, granular activated carbon (GAC), ion-exchanged resins, air-strippers, and bioremediation are used for contaminate removal. These work on many contaminants. However, there is not an readily available cost-effective remedy for uranium.
GAC has been commercially used as an adsorbent for contaminants in water. It is cheap and treatment technology hardware is readily available commercially for its use. Even though GAC is a good adsorbent medium for many contaminants, such as VOCs, it is not efficient for certain metals, particularly uranium. Thus, there has been a need for a material by which contaminating metals and certain organic compounds may be removed from aqueous media.
The present invention provides a solution to this need by providing a material that can be used alone or with GAC to make it a good adsorbent for uranium, for example, without loosing the affinity for other contaminants. The material is a sol-gel and/or sol-gel and GAC mixture.
Sol-gels or aerogels, as commonly known, by themselves have not in the past been cost-effective to use. However, in an example of a composite, made in accordance with the invention, only 20% or less is an aerogel and the composite is a much better adsorbent for uranium than the aforementioned treatment technologies.
It is an object of the present invention to provide for the removal of contaminant metals and organic compounds from aqueous media.
A further object of the invention is to provide solid materials for removal of contaminating metals and organic compounds from aqueous media.
Another object of the invention is to provide for the removal of uranium from aqueous media.
Another object of the invention is to provide a material composed of a sol-gel and/or a sol-gel and a solid support mixtures for removing contaminating metals and organic compounds from aqueous media.
Another object of the invention is to provide a material composed of a sol-gel and/or a sol-gel and granulated activated carbon mixtures for removing contaminating metals and organic compounds from aqueous media.
Other objects and advantages of the invention will become apparent from the following description and accompanying drawings. The invention involves the removal of contaminating metals, such as uranium, and organic compounds from aqueous media. The invention involves a solid material that may be in molded, granular, or powder form, and the solid material adsorbs the metal and the organics leaving a purified aqueous stream. The solid materials are sol-gel and/or sol-gel and granulated activated carbon (GAC) mixtures. After adsorbing the contaminants, the contaminated solid material can be disposed of or the contaminant can be removed and the solid materials recycled. The species-specific adsorption occurs through specific chemical modifications of the solid materials tailored towards the contaminant(s).